Method for harvesting a blueberry field

ABSTRACT

The method for harvesting a blueberry field comprises the steps of carrying a number of empty blueberry containers on a first pair of lower arms of four-arm lift assembly of a blueberry harvester; transferring a first empty blueberry container onto a second pair of lower arms of the lift assembly; filling the first blueberry container with blueberries, and depositing the first blueberry container on the ground as soon as it is full. The steps of transferring, filling and depositing are repeated with each of the empty blueberry containers carried on the lift assembly of the harvester.

FIELD OF THE INVENTION

This invention pertains to commercial blueberry harvesting methods, andmore precisely the present invention pertains to the handling ofblueberry containers in a blueberry harvesting operation.

BACKGROUND OF THE INVENTION

In a common commercial blueberry harvesting operation, the harvestersare mounted to relatively large farm tractors. Generally, a platform isprovided on the back of the tractor to carry a number of empty blueberrycontainers and a number of full blueberry containers. The full blueberrycontainers are carried on the platform until most or all the blueberrycontainers are full. The harvester is then driven to the edge of a fieldwhere the containers are unloaded and transferred to a flat bed truckfor example and carried to a warehouse or a processing plant.

Upon unloading the full blueberry containers to a shuttle truck, theharvester is reloaded with empty blueberry containers and harvesting isresumed.

For reference purposes, examples of blueberry and cranberry harvestersof the prior art are identified in the following publications:

-   U.S. Pat. No. 2,037,624 issued to H. J. Franklin on Apr. 14, 1936;-   U.S. Pat. No. 2,795,099 issued to L. C. Getsinger on Jun. 11, 1957;-   U.S. Pat. No. 3,616,630 issued to G. L. Gray et al. on Nov. 2, 1971;-   U.S. Pat. No. 3,648,447 issued to C. G. Burton on Mar. 14, 1972;-   U.S. Pat. No. 3,724,168 issued to H. W. Cassady Jr. et al. on Apr.    3, 1973;-   U.S. Pat. No. 4,862,683 issued to R. D. Bragg et al. on Sep. 5,    1989;-   U.S. Pat. No. 5,024,052 issued to R. D. Bragg et al. on Jun. 18,    1991;-   U.S. Pat. No. 5,369,944 issued to O. Robichaud on Dec. 6, 1994;-   U.S. Pat. No. 5,375,403 issued to G. E. Collins et al. on Dec. 27,    1994;-   U.S. Pat. No. 6,000,203 issued to L. H. Weatherbee et al. on Dec.    14, 1999;-   U.S. Pat. No. 7,716,909 issued to Dario Hebert on May 18, 2010;-   CA Patent 1,249,727 issued to R. D. Bragg et al. on Feb. 7, 1989;-   CA Patent 1,318,135 issued to R. D. Bragg et al. on May 25, 1993.

The blueberry picking device described in U.S. Pat. No. 7,716,909 issuedto Dario Hebert herein above is particularly appropriate for mounting tothe front end of a small tractor. It is appropriate for mounting to thefront end of a small tractor of the type that is used on commercial lawnmowers and hobby farm equipment for examples. These small tractors havea capacity between 25 and 40 hp., and a weight of about 1600-1800 lbs.

For comparison, the older blueberry harvesters such as the onesdescribed in U.S. Pat. No. 4,862,683; U.S. Pat. No. 5,369,944 and U.S.Pat. No. 6,000,203 for examples, are mounted to larger tractors whichcould weight between 2500-7,000 lbs and more. The footprint pressure ofthese large tractors is relatively high as they are made to travel ongravel roads, hay fields in dry season and forest floors. The tirethreads on the large tractors are made for traction rather than lowsurface pressure. The tire threads are not made to be gentle to theplants and root systems on which they travel. The V-shape threads of afarm tractor wheel for example, has aggressive thread edges that canshear the root system of blueberry plants, just from the weight of thetractor itself. It is believed that such breakage of the root systems ofblueberry plants can adversely affect crop during the next season.Although blueberry plants need pruning, it is believed that damage tothe deep root systems and to the creeping stems (rhizome or surfaceroots) of blueberry plants should be avoided to maintain good plantproduction.

The operation of the large blueberry harvester requires a constantforward motion by the tractor. When one of the wheel encounters anobstruction, such as a bolder, more power is applied to the wheels fromthe engine's governor, so that the tractor can roll over thatobstruction without faltering. Every time a large torque is applied tothe wheel, the sharp V-threads of the wheels are susceptible of damagingthe root systems and the surface stems (rhizomes) of some blueberryplants.

The Hebert blueberry picking head (U.S. Pat. No. 7,716,909) has openedan opportunity for harvesting blueberries using lighter machines.Moreover, the Hebert picking head is operated in a repetitive back andforth movement where excessive wheel torque on the tractor is neverrequired. If an obstruction is encountered, the natural back-and-forthrocking motion of the machine can overcome it.

Also, the smaller and lighter tractors used to operate the Hebertpicking head reduce soil compaction and create less plant damage in ablueberry field. The smaller lawn-type tractors mentioned above have alow footprint pressure, for being designed to operate on lawns andgardens that are watered and aerated on a regular basis. The tires onthese tractors are relatively wider and the thread pads are large andclosely spaced. Plant damage is reduced by both the tires profile and alighter tire work due to the nature of the Hebert harvesting head.

The Hebert picking head has created an opportunity for a method forharvesting a blueberry field, without applying damaging pressure to theroot systems of blueberry plants.

However, these smaller machines cannot carry as many blueberrycontainers as the larger tractors. This reduction in carrying capacitycan represent an impediment to productivity if harvesting must beinterrupted to transport each full berry container to an access road atthe edge of a blueberry field.

Therefore, it is believed that there is a need in the blueberry farmingindustry for a new method for handling berry containers with the smallermachines such that the productivity of a picking head on a small tractoris comparable to the work of the larger harvesters on large farmtractors.

SUMMARY OF THE INVENTION

In the present invention, there is provided a method for harvestingblueberries with a small tractor wherein the productivity is comparableto the larger harvesters. In the new method, the harvester carries anumber of empty blueberry containers and each blueberry container isdeposited on the ground in a specific way as soon as it is full.Harvesting continues in one of the empty containers. Because of thismethod the ground pressure of the harvester is always kept relativelylow.

In a first aspect of the present invention, there is provided a methodfor harvesting a blueberry field comprising the steps of: carrying anumber of empty blueberry containers on a four-arm lift of a blueberryharvester. Empty blueberry containers are transferred, one at the timeto the right side of the four-arm lift, under the end of a longitudinalconveyor. The first empty blueberry container under the longitudinalconveyor is filled with blueberries. This first blueberry container isdeposited to the ground as soon as it is full. The above steps oftransferring, filling and depositing are repeated until all the emptyblueberry containers are full.

In another aspect of the present invention, there is provided a methodfor harvesting a blueberry field, comprising the steps of: carrying afirst and second blueberry containers on respective arm-pair of afour-arm lift mounted to the rear end of a blueberry harvester. Thefirst blueberry container is filled with blueberries. The first andsecond blueberry containers are deposited side-by-side on the groundusing the four-arm lift, as soon as the first blueberry container isfull of blueberries. The present method also includes the steps ofmanoeuvring the blueberry harvester forward and backward and selectivelypicking up the second blueberry container with the right side of thefour-arm lift; raising the second blueberry container under thelongitudinal conveyor, leaving the first blueberry container on theground, and filling the second blueberry container with blueberries.

In yet another aspect of the present invention, the method of harvestinga blueberry field as described above includes the step of movingbackward and away from a harvesting stop line, depositing the fullblueberry container and one empty container side-by-side on the ground,picking up the empty container and raising it under the longitudinalconveyor and moving forward to the last harvesting stop line. The stepof depositing is effected at a distance from an unharvested area of theblueberry field that is farther away from the last harvested strip thanthe width of the harvester.

The space left between the full blueberry container deposited on theground and the last harvested strip in the blueberry field providesspace for the harvester to reposition itself to pick up the emptycontainer without running over any unharvested area of the blueberryfield. Furthermore, the depositing of a full container and the pickingup of an empty container under the longitudinal conveyor is effectedwithout turning the harvester around. The steps of depositing andpicking up are done with minimal steering in the field.

Because of the low footprint pressure of the smaller tractor; thelighter tire work associated with the Hebert picking head; the loadlimitation of only one full container, and the minimum steering duringmanoeuvring the harvester to deposit a full container and to pick up anempty one, there is less damage done to the root systems of blueberryplants in a blueberry field. Production of blueberry plants can only beimproved.

This brief summary has been provided so that the nature of the inventionmay be understood quickly. A more complete understanding of theinvention can be obtained by reference to the following detaileddescription of the preferred embodiment thereof in connection with theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the method according to the present inventionis described with the aid of the accompanying drawings, in which likenumerals denote like parts throughout the several views, and in which:

FIG. 1 is a perspective rear view of the small blueberry harvester usedin the present method for harvesting a blueberry field and for handlingblueberry containers when harvesting a blueberry field;

FIG. 2 is a rear view of the small blueberry harvester with blueberrycontainers loaded thereon;

FIG. 3 is a plan view of the small blueberry harvester with containersloaded thereon;

FIGS. 4-7 illustrate four plan views of the small blueberry harvesterrepresenting four different steps in the present method for harvesting ablueberry field and for handling blueberry containers in a blueberryfield.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1, 2 and 3, the preferred blueberry harvester 20 willbe described. The tractor used in the preferred blueberry harvester 20is a relatively small tractor 22 of the type that is used on commerciallawn mowers for example. Examples of such smaller tractors suitable forthe present application are Kubota tractors, models F3680 and F3990.

The footprint pressure of these tractors is designed to be less that thestrength of a sod layer that has been watered, fertilized and aeratedregularly. Even with the added load of a lawn mower deck or a smallbackhoe, the footprint pressure is less that the strength of a commonlawn surface. The tires on these tractors are relatively wide and thethread surfaces are relatively smooth.

A preferred blueberry picking head for mounting on the preferredharvester 20 is the comb-type Hebert picking head 24 as described inU.S. Pat. No. 7,716,909. A transverse conveyor 26 is mounted between thetractor 22 and the picking head 24. The transverse conveyor 26 has adischarge end over the front end of a longitudinal conveyor 28. Thelongitudinal conveyor 28 extends to the side of the tractor 22 and endsup over a berry receiving container 30, supported on a pair of lowerarms on the rear end of the tractor 22.

As mentioned above, the rear end of the tractor 22 has a four-arm forklift assembly mounted thereon. The fork lift assembly has four armsforming two pairs of lower arms 32, 34 that are mounted side-by-side toa common raisable frame 36. The lower arms 32, 34 extend horizontallybackward relative to the tractor 22 and are movable in unison.

The common raisable frame 36 and the lower arms 32, 34 are movable upand down in a fixed vertical telescopic slide 38. The fixed verticalslide 38 is attached to the tractor 22. The movement of the lower arms32, 34 and of the common raisable frame 36 relative to the fixedvertical slide 38 is effected by one or more hydraulic cylinders 40 asshown in FIG. 3. The lower arms 32, 34 are movable vertically from theground surface to a distance equivalent to about the height of ablueberry container 30.

The fixed vertical telescopic slide 38 has a crossbar 42 mountedthereto. A pair of upper arms 44 extends horizontally backward from thecrossbar 42 substantially above the pair of lower arms 34. The upperarms 44 are fixed relative to the lower arms 34. The upper arms 44remain at a same height when the lower arms 32, 34 move up or down.

Each upper arm 44 has a pair of movable flaps 46 mounted and articulatedthereto. The flaps 46 are operable by hydraulic cylinders 48, from avertical position as shown in FIG. 1, to a horizontal position asillustrated in FIGS. 2 and 3. As it will be understood from theillustration in FIG. 2, the flaps 46 are operable to retain a stack ofempty blueberry containers 50 above the lower arms 34, and toselectively release one empty container 50 at the time onto the pair oflower arms 34 under the stack of containers. In use, the empty berrycontainers 50 are stacked by hand on the upper arms 44 with the flaps 46in a horizontal locking position.

In a harvesting operation, the berries picked up by the picking head 24are dumped into the transverse conveyor 26. The berries are moved alongthe transverse conveyor 26 and into the longitudinal conveyor 28. Thelongitudinal conveyor 28 discharges the berries into the receivingcontainer 30 resting on the right side forks 32 of the four-arm liftassembly of the harvester 22. This operation can be better understoodwhen referring to FIG. 3.

While blueberries are being collected into the receiving container 30resting on the right side lower arms 32 of the harvester 20, the stackof empty berry containers 50 is carried on the left side lower arms 34,and on the upper arms 44 above the left side lower arms 34.

The receiving container 30 is raised on the lower arms 32 until aforward segment of its rim is caught as a cantilever under a retainingflap 52. This flap is affixed to the crossbar 42 as can be seen in FIGS.1, 2 and 3.

In normal crops, a stack of four (4) empty containers 50 with one (1)receiving container 30 provide sufficient space for collecting berriesacross blueberry fields classified as medium size to large fields.During each “run”, the harvester 20 carries the load of the emptycontainers 50 plus the load of the partially full receiving container30. When the receiving container 30 is full, it is released to theground as it will be explained later. Therefore, the harvester 20 isnever loaded in excess of one full berry container 30 plus four emptyones 50.

The blueberry containers 30, 50 that are mentioned and illustratedherein have a capacity of about 12-14 cu ft. A container of that sizefull of berries can weigh in excess of five hundred pounds (500 lbs).Therefore, a full berry container 30 is deposited to the ground as soonas it is full in order to maintain a safe tractor footprint pressure.

A safe footprint pressure of a tractor used in the harvesting ofblueberries, is defined as the pressure that is less than the supportstrength of the surface bushes and root systems of the blueberry plantsin a blueberry field.

In the method according to the preferred embodiment, any excessive soilloading pressure is prevented by discharging the receiving blueberrycontainer 30 as soon as it is full. Relatively speaking, the weight ofthe empty containers 50 are negligible for corresponding to the weightof a lawn mower deck, a garden tiller or a similar tractor accessory.The weight of such tractor accessory is included in the design of thetires of the preferred tractor 22 such that the footprint pressure ofthe tractor with accessory is a safe one for soft lawn surfaces.

Referring now to FIGS. 4-7, the preferred method of handling berrycontainers will be described. In FIG. 4, the preferred small harvester20 is illustrated working a blueberry field 60 one strip 62 at the time.The movement of the harvester 20 can be understood as moving in acounter clockwise direction relative to the blueberry field 60, wherethe crosshatched area 64 represents an unharvested area, and theunmarked area 66 represents a harvested area.

When the receiving container 30 is full of blueberries, the harvester 20backs away from its last harvesting stop line 68 in the blueberry field60, in the direction of arrow 70 in FIG. 4. During the backing up alongthe arrow 70, the harvester 20 moves away from the last harvester strip62 a distance of about at least one full width of the harvester 20 intothe harvested area 66 of the blueberry field. This way, the fullblueberry container 30 is deposited to the ground in a location thatwill not hinder the harvesting of a subsequent strip 62 in theunharvested area 64 of the blueberry field.

Referring now to FIG. 5, the harvester 20 having backed up along thearrow 70, the harvester operator lowers the lower arms 32, 34 to theground, and moves the harvester 20 in a forward direction along arrow72, as illustrated in FIG. 5. The result of this movement is that boththe full berry container 30 and the lowermost empty container 50 aredeposited side-by-side on the ground.

The harvester 20 can now be moved backward again in the direction ofarrow 74 in FIG. 6. During this backward movement, the harvester 20 isalso moved sideways a half-width of the harvester toward the lastharvested strip 62. During this backward movement, the lowermost emptyberry container 50′ that was left on the ground is picked up over theright side lower arms 32, and raised under the conveyor 28. That berrycontainer 50′ becomes the next receiving container 30.

Having a receiving container 30 on the right side lower arms 32, theharvester 20 can now be repositioned along the strip 62, along arrow 76in FIG. 7, and resumes harvesting from its last position 68, withouthaving driven over any unharvested area. Also, the harvester 20 is movedfrom its last harvesting stop line 68 and back to its last harvestingstop line 68 without having to turn about and gouge the soil with hardsteering as it is the case with large harvesters during their turningaround in a blueberry field.

The full receiving blueberry container 30 is left on the field for pickup by a dedicated fork lift tractor. This fork lift tractor (not shown)picks the full blueberry containers 30 and carry them to a flat bedtruck or a trailer for example at the edge of the field. The fork lifttractor (not shown) is preferably a front end loader tractor forexample. Again, the footprint loading of that fork lift tractor is alsominimal for carrying only one full container at the time.

In summary, the method for harvesting a blueberry field according to thepreferred embodiment of the present invention is described as follows:

-   -   providing a small and light-weight harvester 20 with a comb-type        blueberry picking head 24;    -   loading a receiving container 30 on a first pair 32 of lower        arms of a four-arm lift assembly on the harvester 20;    -   loading several empty containers 50 on a second pair 34 of lower        arms on the four-arms lift assembly;    -   harvesting a blueberry field in a counterclockwise direction        from the outside in, defining a harvested area 66 outside the        field and a unharvested area 64 in the central area of the        field;    -   harvesting blueberries and filling the receiving container 30        with blueberries;    -   moving the harvester 20 backward from a harvesting stop line 68        and sideways to the right, away from a last harvested strip 62;    -   lowering and depositing the receiving container 30 and one empty        container 50 on the ground side-by-side in the harvested area        66;    -   manoeuvring the blueberry harvester 20 forward, leaving the        empty container 50′ and the full receiving container 30 on the        ground;    -   manoeuvring the harvester 20 backward and sideways with the        first and second pairs of lower arms 32, 34 in a lower position,        and picking up the empty container 50′ on the first pair of        lower arms 32;    -   moving the blueberry harvester 20 forward and sideways to the        left to the last harvesting stop line 68, leaving the full        container 30 on the ground;    -   resuming harvesting of blueberries and filling the empty        container 50′ on the first pair of lower arms 32 with        blueberries; and    -   repeating the steps of depositing the receiving container 30 on        the ground, manoeuvring and picking an empty containers 50′,        until all the empty containers 50 on the second pairs of arms        have been filled with blueberries.

The transfer of an empty container 50′ under the longitudinal conveyor28 can be effected in about one minute or so. The harvester 20 hasminimum downtime so that productivity of the smaller harvester 20 is ashigh as other more conventional harvesters. The harvester 20 maintains afoot print loading that is very small as compared to the harvesters ofthe prior art.

What is claimed is:
 1. A method for harvesting a blueberry fieldcomprising the steps of: providing a blueberry harvester with acomb-type blueberry picking head mounted to the front end thereof;carrying a number of empty blueberry containers above a first pair oflower arms on the back end of said blueberry harvester; releasing afirst blueberry container onto said first pair of lower arms;transferring said first blueberry container onto a second pair of lowerarms on said back end of said blueberry harvester; said step oftransferring comprising the steps of operating said first and secondpairs of lower arms in unison; depositing said first container from saidfirst pair of lower arms to the ground; manoeuvring said blueberryharvester forward and backward and picking up said first container fromthe ground onto said second pair of lower arms; selectively releasinganother blueberry container from said number of empty blueberrycontainers onto said first pair of lower arms; filling said blueberrycontainer on said second pair of lower arms with blueberries; andrepeating said steps transferring, including depositing said blueberrycontainer on said second pair of lower arms on the ground as soon assaid blueberry container is full, said step of selectively releasing,filling and depositing with each one of said number of empty blueberrycontainers.
 2. The method for harvesting a blueberry field as claimed inclaim 1, wherein said step of carrying a number of empty blueberrycontainers comprises the step of carrying five empty blueberrycontainers.
 3. The method for harvesting a blueberry field as claimed inclaim 1, wherein said step of selectively releasing another blueberrycontainer comprises the step of releasing another blueberry containerfrom a stack of empty blueberry containers.
 4. The method for harvestinga blueberry field as claimed in claim 1, wherein said step ofmanoeuvring further includes the step of backing away from a lastharvesting stop line, and moving forward toward said last harvestingstop line.
 5. The method for harvesting a blueberry field as claimed inclaim 4, wherein said step of backing away included the step of steeringin a right direction a distance equivalent to at least a width of saidharvester.
 6. The method for harvesting a blueberry field as claimed inclaim 1, wherein said step of selectively releasing includes the stepsof retaining said number of empty blueberry containers on upper armswith movable flaps above said first pair of lower arms, raising saidlower arms a distance equivalent to a height of one of said emptyblueberry; operating said flaps from horizontal positions to a verticalpositions for releasing a lowermost one of said empty blueberrycontainers onto said first pair of lower arms, and operating said flapsagain from said vertical positions to said horizontal positions forretaining said empty blueberry containers remaining to said upper arms.7. The method for harvesting a blueberry field as claimed in claim 1,further including the step of harvesting said blueberry field in acounterclockwise direction.
 8. The method for harvesting a blueberryfield as claimed in claim 1, wherein said step of depositing and pickingcomprise the steps of moving away from a last harvested strip and movingtoward a last harvested strip without turning said harvester around. 9.The method for harvesting a blueberry field as claimed in claim 1,wherein said steps of carrying and filling are effected with a blueberryharvester comprising a small lawn-type tractor weighing 1600-1800 lbs.10. The method for harvesting a blueberry field as claimed in claim 9,wherein each of said blueberry containers have a volume of 12-14 cubicfeet.
 11. A method for handling blueberry containers when harvesting ablueberry field, comprising the steps of: carrying a first and secondblueberry containers on respective first and second arm pairs of afour-arm lift of a blueberry harvester; filling said first blueberrycontainer with blueberries while said first blueberry container rests onsaid first arm pair; depositing said first and second blueberrycontainers on the ground side-by-side using said four-arm lift as soonas said first blueberry container is full of blueberries; selectively,picking up said second blueberry container by said first arm pair andleaving said first blueberry container on the ground; and filling saidsecond blueberry container with blueberries.
 12. The method for handlingblueberry containers as claimed in claim 11, further including the stepof carrying four empty blueberry containers on said second arm pairs.13. The method for handling blueberry containers as claimed in claim 11,wherein said steps of depositing and picking up comprising the step ofrepositioning said harvester to one side of said first blueberrycontainer.
 14. The method for handling blueberry containers as claimedin claim 13, wherein said step of depositing is effected at a distanceequivalent to the width of said harvester from an unharvested area ofsaid blueberry field.
 15. The method for handling blueberry containersas claimed in claim 11, further including the step of moving saidharvester backward and away from a harvesting stop line prior to saidstep of depositing, and moving back said harvester to said lastharvesting stop line after said step of picking up.
 16. The method forhandling blueberry containers as claimed in claim 11, wherein said stepof depositing is effected at a distance that is larger than a width ofsaid harvester from an unharvested area of said blueberry field.
 17. Themethod for handling blueberry containers as claimed in claim 11, whereinsaid steps of depositing and picking comprise the steps of backing awayfrom a last harvesting stop line and forward to said last harvestingstop line.
 18. A method for harvesting a blueberry field comprising thesteps of: supporting a first and second blueberry containers on afour-arm lift assembly mounted to the rear end of a blueberry harvester;filling said first blueberry container with blueberries; depositing saidfirst and second blueberry containers on the ground side-by-side usingsaid four-arm lift assembly as soon as said first blueberry container isfull of blueberries; selectively picking up said second blueberrycontainer with said four-arm lift without turning said blueberryharvester around, leaving said first blueberry container on the ground;and filling said second blueberry container with blueberries.
 19. Themethod for harvesting a blueberry field as claimed in claim 18, whereinsaid steps of depositing and selectively picking up include the steps ofbacking away from a last harvesting stop line and moving forward towardsaid last harvesting stop line.
 20. The method for harvesting ablueberry field as claimed in claim 19, wherein said step of backingaway included the step of steering in a right direction a distanceequivalent to at least a width of said harvester.